Several techniques for locating wireless devices involve the Mobile Station (MS) making measurements of the signals transmitted by the base stations of a wireless communication network. (The term MS or Mobile Station, as used herein, refers to any type of wireless phone or other mobile device having a radio communications capability.) These techniques are known by the acronyms EOTD, AFLT, OTD and ECID.                Enhanced Observed Time Difference (EOTD) is a location technique defined in the ETSI 3GPP Technical Specification 43.059 in which a GSM MS makes relative time difference measurements of the beacon signals transmitted by geographically distributed base stations, where these measurements are used to compute a position.        Advanced Forward Link Trilateration (AFLT) is a technique defined in the TIA IS-95 and CDMA 2000 standards in which a CDMA MS makes relative time difference measurements of the pilot signals transmitted by geographically distributed CDMA base stations, where these measurements are used to compute a location.        Observed Time Difference (OTD) is a location technique defined in the ETSI 3GPP Technical Specification 23.271 in which the User Equipment (UE), which is essentially a mobile station in a UMTS network, makes relative time difference measurements of the signals transmitted by geographically distributed Node Bs (base stations in a UMTS system), where these measurements are used to compute a location.        Enhanced Cell Identification (ECID) is a technique used to locate GSM MSs in which the MSs perform received power level measurements of the signals transmitted by geographically distributed GSM base stations, where these measurements are used to compute locations.        
All of these location techniques involve a MS measuring signals whose characteristics vary as a function of the distance between the MS and the Base Stations transmitting the signals. In addition, all of these location techniques require knowledge of key cell site information. Such key cell site information may include cell identification information and transmit antenna location. In addition, some of these location techniques require additional information about the transmitters, such as transmitter signal timing, signal transmit power, and signal propagation or signal loss in the environment. This information can be difficult to obtain from wireless network operators because it is dynamic and distributed across multiple data bases. This information may be difficult to obtain and maintain across multiple wireless network operators, as some operators may not be willing to cooperate and provide this information. The accuracy of each of the location techniques described above will be improved if a larger number of the base station signals are used in the location solution, which is possible when the transmit signals across multiple wireless networks are available. The accuracy of each of these techniques is dependent upon the number and quality of the signals available for measurement, and so the ability for a location solution to utilize these signals across multiple wireless networks will provide better performance than could be achieved if the measurements were limited to the signals of a single wireless network.
One goal of the present invention is to provide an automatic way to detect the existence of one or more useful wireless transmitters, determine the cell identification information so that each transmitter can be referred to later, determine the transmitter antenna locations, determine the transmitter timing, determine the transmitter power level, and determine the signal power loss as a function of location, so that any such wireless transmitter can be used to locate mobile stations.